1. Field of the Invention
The present invention belongs to a technical field of a connector wherein a female terminal is inserted in a chamber of a housing.
2. Related Art
A connector has been known, as shown in FIG. 17A, wherein through chambers 82, in several rows and columns in the directions of height and width, are formed in a housing 81 in parallel to each other, a female terminal 84 being approximately box-shaped in the front half, thus having an approximately rectangular section, and being connected to an electric wire 83 in the back is inserted into and fixed in each of the chambers 82, and male terminals of a counterpart connector are inserted into these female terminals 84 to make mechanical connections as well as electrical connections (refer to, for example, Japanese Provisional Patent Hei 8-106944). A port 85 opens in the top end of the above-mentioned female terminal 84 to receive a male terminal. A splicing part 86 is formed in the back of the female terminal 84 to connect an electric wire 83. A concave fixing part 87 is formed in an intermediate part of the female terminal 84. A hook of a lance 88 that is flexibly formed in a chamber 82 of the housing 81 fits into this concave fixing part 87 to make a primary fixing of the female terminal 84 to the housing 81. Moreover, a fixing piece 90 of a retainer 89 that is fitted into the housing 81 is set at the back of a stabilizer 91 that is formed on the top of the intermediate part of the female terminal 84 to make a secondary fixing of the female terminal 84 to the housing 81.
Apart from this, a connection structure between a female terminal of this kind and a male terminal has been disclosed in Japanese Provisional Patent Hei 9-232021. As shown in FIG. 17B, to hold an inserted male terminal 92xe2x80x2, a leaf spring 93xe2x80x2 is integrally formed inside the terminal proper 94xe2x80x2 of a female terminal 84xe2x80x2. Moreover, a separate reinforcing leaf spring 95xe2x80x2 is blanked out together with the terminal proper 94xe2x80x2 and this reinforcing leaf spring 95xe2x80x2 is bent on the inner side of the main leaf spring 93xe2x80x2 to form double springs and ensure a sufficient contacting force.
Further, in Japanese Provisional Patent Hei 5-135819, a female terminal has been disclosed wherein a leaf spring is integrally formed inside the terminal proper and the leaf spring is bent sideways and approximately circularly to form a round part. The front half of this terminal proper is formed into an approximately box-shaped form that comprises a bottom wall, side walls rising from both ends, in the width direction, of the bottom wall, and an outer upper wall and an inner upper wall which extend from the top ends of the respective side walls towards the top ends of the opposing side walls and overlap with each other above and below. As the terminal proper is formed into an approximately box-shaped form having upper walls overlapping with each other, it has merits that the above-mentioned front half is hardly deformed even if, for example, a worker inadvertently steps on it and external forces are exerted to the terminal proper and that the leaf spring inside the terminal proper is protected reliably.
However, in the above-mentioned female terminal 84xe2x80x2 having double springs, as two leaf springs 93xe2x80x2, 95xe2x80x2 overlap with each other, the female terminal 84xe2x80x2 becomes bulkier in the direction of height, preventing compactification of the connector. Further, the female terminal having a round part being bent sideways into an approximately circular arc becomes bulkier in the direction of width due to this round part, preventing compactification of the connector.
In the case of the female terminal 84xe2x80x2 having double springs, as each of the leaf springs 93xe2x80x2, 95xe2x80x2 is formed by bending, a gap is formed between two unrestricted leaf springs due to springbacks. As the dimension of this gap is a cumulative result of steps of forming two springs, it is difficult to accurately control this dimension in the production. Hence it is hard to avoid dispersion in this gap dimension. This poses a problem. At the time of use, the point of inflection of the spring constant at which the main spring 93xe2x80x2 contacts the reinforcing spring 95xe2x80x2 and both springs 93xe2x80x2, 95xe2x80x2 start to be deformed varies from product to product. Thus contacting forces are not stable and vary from product to product.
When a female terminal is blanked out of a sheet metal and shaped into a desired form by bending, the smaller is the developed shape of the female terminal, the greater is the efficiency of yielding the developed shapes of the terminal from a material of a given area, thus the cost is lowered. Furthermore, the smaller is the number of bending operations, the simpler is the process of production. This also contributes to reduction in cost.
As a connector is used in combination with a counterpart connector, compactification of the counterpart connector is also desired. Further, if there is an error in assembling a male terminal in the counterpart connector, the male terminal may be assembled to be slightly slant in relation to the housing. In the worst case, such a male terminal may cause a trouble that it can not be inserted into a female terminal.
The above-mentioned stabilizer 91 can exhibit a function of preventing so-called inverse insertion; if the female terminal 84 is inserted into the chamber 82 of the housing 81 in an incorrect orientation, for example, upside down, the stabilizer 91 will catch the entrance of the chamber 82 to prevent further insertion. Because of this function, the female terminal 84 and the retainer 89 are brought to a proper positional relationship and the female terminal 84 is fixed by the retainer 89. However, as the stabilizer 91 is to be fixed by a fixing piece 90 of the retainer 89, the stabilizer 91 is provided on the top of the intermediate part of the terminal proper. Accordingly, the front portion of the terminal proper ahead of the stabilizer 91, even if it is inverted upside down, would be inserted. This, in turn, would make the worker forcefully insert the female terminal 84 further, resulting in a damage to the chamber and nearby of the housing 81.
When a continuity test or the like is given to a female terminal of a connector, a test jig having a shape identical to that of a male terminal is inserted into the female terminal. When the test jig is used repeatedly, the jig may be deformed. If such a deformed jig is forced into a female terminal, the lead spring, etc. will be damaged to cause a trouble.
In view of the above-mentioned problems, the present inventor has proposed, in Patent Application No. Hei 10-219753, an invention to solve some problems. That invention, however, has limitations to compactification of the connector and the developed shape of the connector since the leaf spring has a round part and the round part is provided independently of a wall constituting the front half of the terminal proper. Accordingly, one objective of the present invention is to form the front half of a terminal proper into an approximately box-shaped form so as to protect a leaf spring, etc., to use an upper wall so as to form a leaf spring, to form a bead on the leaf spring so as to reduce the number of leaf spring to one and compactify the female terminal in both the directions of height and width as much as possible, to secure sufficient contacting force reliably and move a contacting part of the leaf spring forward, to reduce the length of insertion of a male terminal so as to compactify the counterpart connector and increase the tolerance of the connector to slant of the male terminal, to make the developed shape of the female terminal smaller so as to achieve efficient use of material, reduce the costs and simplify the production process.
To accomplish the above-mentioned objective, the present invention is a female terminal for a connector that is to be inserted into a chamber of a housing of a connector and is to receive a male terminal, said female terminal comprising: a terminal proper having a box-shaped front half that can be inserted into said chamber of the housing, having a port that opens in the front end and receives a male terminal, and having a splicing part that is in the back and is to be connected to an electric wire; and a leaf spring having a root end that is integral to the front half of said terminal proper, having a top end that extends forward inside the front half of said terminal proper, and being to be flexed in the direction of height; said front half of the terminal proper comprising a bottom wall, side walls rising from both ends in the width direction of said bottom wall, and an outer upper wall and an inner upper wall extending from the top edges of said respective side walls toward the top edges of the opposing side walls, said inner upper wall having a front inner upper wall and a rear inner upper wall, said leaf spring being formed by separating said rear inner upper wall from the side wall, with the rear end of said rear inner upper wall being left intact, and said leaf spring having a bead with a curved section to increase the flexural rigidity.
According to the present invention, an electric wire is connected to the splicing part of the terminal proper, and the female terminal is inserted into a chamber of the housing. When this connector is opposed to a counterpart connector and the male terminals of the counterpart connector are inserted into the respective female terminals of the connector, the leaf springs will be pressed to contact the male terminals to make mechanical connections and electric connections between both connectors.
In this case, as the front half of the terminal proper is formed into an approximately box-shaped form, the front half will be hardly deformed, thus the leaf spring, etc. inside the front half will be protected reliably. Further, as a bead is formed on the leaf spring, the flexural rigidity of the leaf spring is increased and a sufficient contacting force can be provided by a single leaf spring without provision of a reinforcing spring. Moreover, as the female terminal does not have any reinforcing spring nor a round part, the female terminal can be compactified in both directions of height and width. Further, as no reinforcing spring is provided, the spring constant has no point of inflection, and the contacting force of each product is stabilized. Furthermore, as the flexural rigidity of the leaf spring is increased, a sufficient contacting force is generated even if a contacting part of the leaf spring is shifted forward close to the port. As a result, the length of insertion of a male terminal is shortened, and in turn, the housing of the counterpart connector that contains the male terminal is shortened and compactified and its tolerance to slant of the male terminal is also increased. Moreover, as the leaf spring is made out of the inner upper wall, the developed shape is smaller in comparison with a case when a leaf spring is provided independently, and in turn, the efficiency of layout of developed forms is improved and the cost is reduced, and furthermore, as bending steps dedicated to the leaf spring are eliminated, the production process is simplified.
In the female terminal for a connector according to the present invention, the front half of the terminal proper is formed into an approximately box-shaped form to protect a leaf spring, etc., and a leaf spring is made out of the inner upper wall and a bead is formed on the leaf spring to increase its rigidity. As a result, the number of leaf spring is reduced to one, the female terminal can be compactified in both directions of height and width, a sufficient contacting force can be provided reliably, the contacting part of the leaf spring can be shifted forward, the length of insertion of the male terminal can be shortened and the counterpart connector can be compactified, and the tolerance to slant of the male terminal is increased and the yield of connectors can be improved. Moreover, the developed shape can be made smaller to improve the efficiency of layout of developed shapes and, in turn, to reduce the costs, and the bending steps dedicated to the leaf spring can be eliminated to simplify the production process.